The combo tests simultaneously for antibody to HIV and p24 antigen, a protein component of the virus. The RNA test looks for the virus's genetic material. In other words, both p24 antigen and RNA are direct tests for the virus itself, whereas antibody measures the immune system's response to the virus.
It is not possible to have HIV for 12 months and have a negative antibody tests -- regardless of the RNA test result.
Having also looked at your thread on the HIV community forum, I agree with the advice there -- i.e. you could not have acquired HIV from the exposure described, even if your girlfriend had HIV, which probably she did not.
Copyright 1994-2018MedHelp.All rights reserved. MedHelp is a division of Vitals Consumer Services, LLC.
The Content on this Site is presented in a summary fashion, and is intended to be used for educational and entertainment purposes only. It is not intended to be and should not be interpreted as medical advice or a diagnosis of any health or fitness problem, condition or disease; or a recommendation for a specific test, doctor, care provider, procedure, treatment plan, product, or course of action. MedHelp is not a medical or healthcare provider and your use of this Site does not create a doctor / patient relationship. We disclaim all responsibility for the professional qualifications and licensing of, and services provided by, any physician or other health providers posting on or otherwise referred to on this Site and/or any Third Party Site. Never disregard the medical advice of your physician or health professional, or delay in seeking such advice, because of something you read on this Site. We offer this Site AS IS and without any warranties. By using this Site you agree to the following Terms and Conditions. If you think you may have a medical emergency, call your physician or 911 immediately.